Permanent magnet and process for producing permanent magnet

Abstract

The present invention relates to a permanent magnet manufactured by steps of: pulverizing a magnet raw material; mixing the pulverized magnet raw material with a rust preventive oil in which a Dy compound or a Tb compound is dissolved, thereby preparing a slurry; compression molding the slurry to form a molded body; and sintering the molded body.

1 . A permanent magnet manufactured by steps of:
 pulverizing a magnet raw material;   mixing the pulverized magnet raw material with a rust preventive oil in which a Dy compound or a Tb compound is dissolved, thereby preparing a slurry;   compression molding the slurry to form a molded body; and   sintering the molded body.   
     
     
         2 . The permanent magnet according to  claim 1 , wherein the Dy compound or the Tb compound is unevenly distributed in a grain boundary of the magnet raw material after sintering. 
     
     
         3 . The permanent magnet according to  claim 1 , wherein the Dy compound or the Tb compound is contained in an amount of from 0.01 to 8 wt %. 
     
     
         4 . A permanent magnet manufactured by steps of:
 pulverizing a magnet raw material;   mixing the pulverized magnet raw material with a rust preventive oil in which fine Dy particles or fine Tb particles are dissolved, thereby preparing a slurry;   compression molding the slurry to form a molded body; and   sintering the molded body.   
     
     
         5 . The permanent magnet according to  claim 4 , wherein the fine Dy particles or the fine Tb particles are unevenly distributed in a grain boundary of the magnet raw material after sintering. 
     
     
         6 . The permanent magnet according to  claim 4 , wherein the fine Dy particles or the fine Tb particles are contained in an amount of from 0.01 to 8 wt %. 
     
     
         7 . A method for manufacturing a permanent magnet, comprising steps of:
 pulverizing a magnet raw material;   mixing the pulverized magnet raw material with a rust preventive oil in which a Dy compound or a Tb compound is dissolved, thereby preparing a slurry;   compression molding the slurry to form a molded body; and   sintering the molded body.   
     
     
         8 . The permanent magnet according to  claim 7 , wherein the Dy compound or the Tb compound is contained in an amount of from 0.01 to 8 wt %. 
     
     
         9 . A method for manufacturing a permanent magnet, comprising steps of:
 pulverizing a magnet raw material;   mixing the pulverized magnet raw material with a rust preventive oil in which fine Dy particles or fine Tb particles are dissolved, thereby preparing a slurry;   compression molding the slurry to form a molded body; and   sintering the molded body.   
     
     
         10 . The permanent magnet according to  claim 9 , wherein the fine Dy particles or the fine Tb particles are contained in an amount of from 0.01 to 8 wt %. 
     
     
         11 . The permanent magnet according to  claim 2 , wherein the Dy compound or the Tb compound is contained in an amount of from 0.01 to 8 wt %. 
     
     
         12 . The permanent magnet according to  claim 5 , wherein the fine Dy particles or the fine Tb particles are contained in an amount of from 0.01 to 8 wt %.